While the prior art dealing with cargo vessel construction and containerized shipping and handling of containerized cargoes is very extensive, the prior art has not developed a portable modular deck which may be used in a general cargo vessel of the type that is a common carrier of widely varying kinds of freight.
For example, the prior art U.S. Pat. No. 3,537,414 issued to Jerome L. Goldman teaches the use of containerized pallets. In this prior art a means is provided for automatically actuating the support elements when the pallet strikes an object such as another pallet below which causes the pallet to automatically extend its supporting elements at the appropriate time. Such a system works well with a uniform sized cargo, such as might be found on a vessel dedicated to carrying semi-finished materials between two factories. The problem with this prior art patent of Goldman, however, is that it is not able to carry a wide variety of types and sizes of general cargo at the same time. For example, if bulk grain were placed in the hold of a vessel and then Goldman's pallets were placed on top of the grain, the actuating means on the pallets would simply bury themselves in the grain. The pallets, therefore, would not attach themselves to the supporting bulkheads of the vessel. Another example is that of the common problem of carrying tall cases of machinery. If Goldman's pallets were sized to average size cases, a tall case would block the actuating mechanism of a pallet placed above it. If the pallets were sized for carrying tall cases, spaced would be wasted when they carried small cases. In any case, such a ship would not be able to carry a wide variety of types of cargo, such as are carried aboard common carries, but only types of cargo that will fit in the pallets.
Also in the prior art the mechanism of the support elements are such that they are manufactured into the pallets and/or containers themselves and thus the whole deck is taken out of service when damage occurs to the support mechanism.
In another example, the prior art of U.S. Pat. No. 3,415,214 issued to Jerome L. Goldman; cargo is stowed on "receivers" which are described as being pallets or containers. The receivers rest upon manually placed support bars that are placed under each corner. The support bars extend from holes in the bulkheads to holes in deep flanges between each receiver. This system has a number of problems that make it impractical: the manual placing of the bars requires that longshoremen be aboard the vessel and that numerous ladders and platforms be available for them to reach the holes. Also this system requires a lot of special construction in the vessel in order to leave holes in the bulkheads and still maintain watertight compartments. Also, it would be very difficult to carry such cargoes as bulk grain or liquids in a vessel built for this system because the grain or liquids would run thru the holes. Also the wide flanges which protrude into the cells would interfere with cargo that might otherwise be placed across two or more of the receivers.
Further, the prior art containers and pallets have not been such that they can be stored in a space less than the spaced that they utilize as carriers of cargo. Such that a container takes up the amount of space that a container takes up whether it is loaded or unloaded and thus, when the container is not in use, it still occupies the same amount of sapce that it would if it were loaded. There is no way that an enclosed container can be rearranged to occupy less space.
Also, in the the prior art the cargo fit inside the container and cannot span across several containers. That is, several pallets placed side by side cannot jointly support layer pieces of cargo because cell structure -- guideway structure gets in the way. Also, the prior art has generally dealt with either container vessels or general cargo vessels and the prior art has not attempted to provide a portable deck which can be used in a general cargo vessel as well as in a containerized ship so that the deck allows a general cargo vessel to become a limited containerized ship. Also, by using the portable decks in general cargo vessels better cargo and weight distribution can be perfected because of locating the decks at various positions in the hold of a general cargo vessel; to provide for better and proper weight distribution over the vessel. This is important because it provides greater stability for the sea going vessel, as well as a more dense stowage of the cargo.